Extensible structure



(No ModevL) i y W. W. frmlwsolv EXTENSIBLB STRUCTURE'.

No. 357,444. Patent@ yWKK N. PETERS, PhnwLimagmphnr, washmglm D. C,

NITE Tatras IVILLIAM IV. ATKINSON, OF CHICAGO, ILLINOIS.

EXTENS'IBLE STRUCTURE.

SPECIFICATION .forming part of Letters Patent No. 357,444, datedFebruary 8, 1887.

Application tiled November 9, 1885. Serial No. 182,244.k (No model.)

T all whom it may concern:

Be itknown that I, WILLIAM W. AIIrINsoN, of Chicago, in the county ofCook, and in the State of Illinois, liaveinvented certain new and usefulImprovements in Extensible Structures; and I do hereby declare that thefollowing is afull, clear, and exact description thereof.

My invention relates to extensible structures for use in scaffolding,Iire-escapes, &c., as will be hereinafter described.

In the drawings, Figure l represents a perspective view of Inystructurepartly extended; Fig. 2, a similar view showing my structure fullyextended; Fig. 3, a detail View of the structure and base-connection.

A is the base of my device, which may either rest directly upon theground or may form part ot' a truck, and upon this base the lower orhorizontal member, B, of my device rests. To the base A is hinged thelower end of a member, C, the means employed for this connection beingpreferably a swiveled hingejoint, a.

D is a member hinged or pivoted at one end to the member B, and exactlymidway of its length the member D is pivoted to the member C at a pointthat is distant one-third of the latters length from the hinged end` theother end of said member D being pivoted to a member, Fl, and thislatter member is pivoted atb to another member, F, on the same verticalline as the pivotal connection of the members C and D. This member F ispivotally connected at c to the member` C on the vertical line withpivotal connection of the members B and D, while at d on` the same linepivotal connection is established between the member E and anothermember, G, the latter being' also pivotally connected at its lower en'dto the upper end of the member C, as shown at e, and so on, the membersbeing duplicated from this point, according to the length of thestructure required, the pivotal points being equidistant from eachother, sothat the entire series of members or levers thus united formquadrilaterals. The lower or horizontal member, B, lies iiat upon thebase A, and has free movef ment thereon, so as to permit the lower endof the member D to approach the lower end of the one, C, as thestructure is extended.

To the base A. is preferably secured a windlass, H, for a rope or cable,I, which is passed from thence over apvotally-hung pulley, g, on thelower end of the member F, and then over a similar pulley on the lowerend of the member E, then back over another vpulley on the lower end ofthe member G, andsoon back and forth over other pulleys secured to thelower ends of the respective members of the entire structure until theupper limit is reached, and at this pointsaid rope or cableis made fast,sothat by operating the windlass H said rope or cable is wound upthereon, thus causing the structure to be rapidly elevated t0 anydesirable height. The windlass H is provided with a pawl and ratchet,f,so as to automatically secure the structure at any height to which itmay be elevated, and by further winding of the windlass after thestructure is entirely extended the slack of the rope or cable I is thusentirely taken up.

The several members above the one, B, are composed, respectively, oftwoseotions,which are laid one upon the other in such a manner as to formshoulders 7L, andwhen the structure is fully extended the shoulder ofone section abuts against those adjacent thereto both above andbelow,and thereby brace said structure and compensate for any strainthat may be brought thereon.

To each of the several members, I prefer to unite a rail, K, by means ofrounds t', so as to form a short ladder, which, whenthestructure isentirely extended, will together form a perfectly straight continuousdouble ladder, extending from the base A upward; but when the structureis only partly extended these short ladders form an angular ascent, sothat a desired elevation may be readilyreached by climbing one of saidshortladders, then changing to another, and so on to the limit ot" thestructures extension.

It is obvious that I may unite the rails Kto the respective members ofthe frames on one side only ofthe structure, and thus form a singlecontinuons ladder, when said structure is fully extended, withoutdeparting from the spirit of my invention.

At -any point or points of the structure deemed desirable I secure eyes7s, which serve as means for securing grapplingironsor braces adapted toconnect said structure with a buildfoo ing or other support; or theseeyes may be employed as a means for connecting an auxiliary ladder, sothat the latter maybe variously used without interfering with partiesengaged upon the mainladder formed by the extension of the structure. Ineases where the structure may be used by iiremen this means ofconnecting an auxiliary ladder will be found of great utility, as thelatter may be employed to reach one elevation by one set of menwithoutin any way interfering with the operation of another set usingthe extended structure to reach a great altitude. By the pivotalrelative arrangement of the several members ofthe structure a leversystem is produced, whereby an operator standing upon the structure whenin its collapsed position can by drawing on the rope or cable I extendthe structure and raise himself to any elevation within its limit. Ifpreferred, the windlass mechanism for extending the structure may beplaced on the upper portion thereof, instead of at the base, therebyaiding the operator in extending said structure and raising himselftherewith.

If desired, a staging can be formed at any point or points of thestructure when partially extended by placing boards upon the rounds ofopposing ladders. The structure may be provided with pins Z,\or othersuitable means to unite the several members when said struct ure iseither partially or entirely extended, so as to lool: and retain it insuch a position independent ofthe hoisting rope or cable, therebyremoving the strain from the latter.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

l. An extensible structure consisting of a series ot pivotally-connectedquadrilateral lever-frames, each having its members offset to formshoulders, in combination with means, substantially as described, forextending and collapsing said structure, as set forth.`

2. An extensible structure consisting of a series of pivotally-connectedquadrilateral lever-frames, each having its several members composed oftwo sections secured one upon the other in such a manner as to formshoulders, in combination with means, substantially as described, forextending and collapsing said structure, as set forth.

3. An extensible structure consisting of pivotally.- connectedquadrilateral lever frames, each having its members offset to form shoulders, in combination with means, substantially as described, forextending and collapsing the structure, and a series of rails convneeted by rounds to the respective members of the frames on one side ofthe structure,whereby a single continuous ladderis formed when saidstructure is fully extended, as setr forth.

Il. An extensible structure consisting of a series ofpivotally-connected quadrilateral le ver-frames, in combination withmeans, substantially as described, for extending and collapsing thestructure, and a series of rails alternately connected by rounds to aportion of the respective members of the frames on both sides oi thestructure, whereby a double-inclined reversing ascent and descent isformed when said structureis partially extended, as set forth. Y

5. Au extensible structure consisting of a series 0f pivotally-coimectedquadrilateral lever-frames having the respective members thereof oifsetto form shoulders, and provided at each end with a pulley, incombination with a cable secured at one terminus of the Structure andpassed over the several pulleys thereon, and a windlass mechanism foroperating said cable, as set forth.

In testimony that I claim the foregoing I have hereunto set my hand, atMilwaukee, in the county of llilwaukeeand State of Wisconsin, in thepresence of two witnesses.

VILLAM XV. ATKINSON.

\\Tit11esses:

S. S. SroU'r, R. A. MCCULLOUGH.

